DESCRIPTION: (Adpated from applicant's abstract) The objective of this project is to develop an assay for the quantitation of oncogene products in cancer cells and tissues. The main effort will be to quantitate the protein encoded by the HER-2/neu oncogene, P185(HER2), since it has been strongly implicated in the biological behavior of breast cancer, and may have prognostic significance. The techniques used will be those of high resolution digital image microscopy and immunohistochemical localization. Immunohistochemical techniques enable the assessment of protein status in tumor cells, specifically excluding other tissue components, and makes it possible to quantitate the protein in an objective manner. Image analysis combined with immunohistochemistry makes it possible to perform HER-2/neu protein level measurements on very small tissues such as derived from biopsy material or needle aspirates, and makes it possible to establish normal levels of expression versus overexpression of gene products.